We plan to extend our initial studies on the stability of the glyceraldehyde adduct at the alpha- and the epsilon-NH2 groups of hemoglobin. These adducts are present as ketoamine adducts and it has become clear that those at the epsilon-NH2 groups of lysine residues are hydrolyzed much more rapidly than those at the alpha-NH2 groups. The effects of various buffers on this hydrolysis will also be studied. Studies with the 2-carbon aldehyde, glyceraldehyde, will be continued. When the initial Schiff base of this aldehyde and a protein rearrange to the ketoamine, a new aldehyde is generated and cross-linking occurs. Experiments designed to determine which adduct(s) of glyceraldehyde and hemoglobin contribute to the inhibition of gelation will be completed.